Currently, combines typically include crop residue spreader apparatus for disposing of straw and other residue separated from the harvested crop onto the field from which the crop was harvested. In addition, some combines have a chaff spreader for spreading chaff residue separated from the grain by the cleaning apparatus or system onto the field. In many instances it is desirable for the straw, chaff and other residue to be spread as evenly as possible over the width of that section of the field over which the combine has just passed and harvested the crop from, to avoid problems resulting from uneven spreading, such as, but not limited to, difficulty in passage of fall tillage tools through residue clumps or thick areas; difficulty in making even straw bales by a baling machine; uneven residue concentration when mulched in the soil; uneven insulation of the field resulting in uneven field warming and thawing and crop emergence during the following planting season; and increased rodent and insect habitat. In some instances, it is also desirable to have an ability to adjust the spreading to compensate for crop type, varying moisture and weather conditions; such as wind and the like, and also combine header width.
U.S. Pat. No. 7,281,973 describes a spreader with vertical rotary impellers and an adjustable flow distributor operable for discharging a flow of straw and other crop residue in a sideward direction for deposition over a field.
Spreaders are known in which two horizontal rotor impellers expel the straw residue. EP 1 031 273 describes a combine harvester having two projection blowers, wherein the material discharge opening of the chaff cutter is in the same plane as the material intake opening of the projection blowers. The periphery of the projection blowers is—starting from the side boundary of the intake opening—delimited by at least partially peripherally extending casing surfaces which are fixed. The two upright surfaces are combined at the centre of the intake opening to form a divider tip whereof the walls extend uniformly in respect of height.
EP 1 269 822 describes a combine harvester having a chaff collector and means for conveying the collected chaff to two projection blowers which are adjustable in three different positions. In active position A the chaff is hurled centrally between the two adjacent projection blowers, where a wedge-shaped guide element divides the supplied chaff flow over the two projection conveyors.
U.S. Pat. No. 7,331,855 describes a spreader with two rotating impellers. The rear of the chopper has an angled discharge mechanism directing the chopped residue into the inlet of the spreader. The spreader is oriented vertically above and rearward of the chopper. Furthermore, the spreader incorporates air intake holes and air fins above the impellers to keep crop residue moving through the impellers without plugging of discharge material.
Although various crop residue spreaders are known which can propel residue a distance equal to about one half the width of a typical combine header, many suffer from shortcomings, including a tendency to provide uneven crop residue distribution or coverage in the side to side direction over the swath. More particularly, for a horizontal spreader, that is, a spreader utilising one or more rotary impellers or other elements rotatable about a generally vertical axis, or an axis oriented or tilted at a small acute angle to vertical, and configured for directing a flow or flows of crop residue sidewardly, it has been found that the resultant coverage has a tendency to be uneven in the sideward direction, for instance, typically thicker toward the outer regions or sides of the swath, and thinner or less uniform closer to the centre of the swath. Another typical problem is loss of straw and other residue through gaps in the spreader area, for instance in the centre between the two rotary impellers or between the chopper and the spreader. It has also been found that a portion of the crop residue may be engaged by the tip of the impeller blades but not conveyed properly along the impeller housing to the spreader outlet. The effect is that an unwanted pile of crop residue is formed on the field in a swath along the centre axis of the spreader.
Meanwhile, larger combines were built having a higher flow of straw and chaff, while the wider headers they are using (nowadays up to 12 m) have a demand of better spreading, and more intensive crop processing in the combine results in more straw and other residues.
Thus, what is sought is a crop residue flow distributor for the discharge outlet of a horizontal crop residue spreader, having a capability to efficiently distribute or guide portions of a discharged flow of crop residue for achieving a desired pattern of the distributed residue, which can include particularly, more even distribution side to side over a region of an agricultural field from which the crop was harvested, to achieve the advantages, and avoid the shortcomings and problems of the prior art devices, discussed above. More specifically the spreader needs to cope with problems of uncontrolled loss of crop residues through gaps and openings of the spreader.
In another aspect, when the crop residue is slid or dropped on the field using a guiding plate instead of a rotary impeller spreader, the crop residue may not be hindered in any way by the guiding mechanism. Known systems provide guiding fingers along each side of the plate, typically oriented towards the centre of the plate to guide the crop residue as it falls on the field. These systems tend to get congested with crop residue, especially when the harvesting machines is tilted sideways when driving on slopes or hills.
Thus it is an object of the present invention to provide a uniform, controlled and unhindered crop residue on the field when harvesting crop in any field or crop conditions, whether using a rotary spreader or a guiding plate. An important aspect is also to keep the harvesting chopper and spreader as clean as possible, avoiding crop residue build-up.